Power switches are conventionally used to couple a load with a supply voltage. In recent years, “smart” power switch devices have been developed which are equipped with one or more diagnostic abilities and protection features, for example against overloads and short circuit events. In some implementations, in a power switch device a MOS transistor may be used as a power switch selectively coupling a load to a supply voltage. Such power switches are for example used in modern automotive and industrial systems instead of conventional fuses and electromechanical switches for low voltage applications with medium to high current loads. In such applications, a first load terminal (also referred to as input terminal) of the power switch device is coupled to a supply voltage, and a second load terminal (also referred to as output terminal) of the power switch device is coupled to a load to be supplied with power. In such configurations, a so-called inverse current condition may occur, where a voltage at the second load terminal (output terminal) is higher than a voltage at the first load terminal (input terminal). Due to parasitic bipolar transistors becoming conducting in such a situation, it may be impossible to turn the power switch device on, which, however, may be desirable for some applications.
In this respect, a conventional power switch device is disclosed in DE 196 06 100 A1.